The Atlantic provinces do elect some of those, but that's not "Conservative" by our definition, they'd be uber-RINOs. Only Alberta is the safe bet for letting into the US, even Saskatchewan and Manitoba are iffy (and as pointed out, BC would only work if you cut the Vancouver region out). The Atlantics, IIRC, are often heavily subsidized, with Newfoundland being the absolute worst. NS would be the best of the lot, but that's not saying much (plus I doubt they would like the fact that if they were admitted as a state, they'd only get 1 Congressmember, as they have the exact same population as Montana).
But they would get 2 US Senators.